git.codelab.vc is Gitea/Forgejo: raw path is /raw/branch/<ref>/, the GitLab-style
/-/raw/main/ returned 404 so the one-command install was broken. The one-liner
now also fetches the script from the stable channel (vetted), not main.
Found in a clean cps sandbox run: a machine without git passes the Node check
but fails later inside 'pi install git:...' with an unclear error. Now checked
up front with an actionable message. CHANGELOG updated.
Decision on optionalDependencies (@modelcontextprotocol/sdk): KEEP. The heavy
install observed in the sandbox (~317 packages) is dominated by npm>=7
auto-installing the Pi peerDependencies stack, not the MCP SDK; removing the
SDK saves little and would make MCP enablement fragile across pi updates.
